[all] Set maximum maxZoom to 21

Numbers greater than 21 trigger various bugs.

CHANGELOG.md

@@ -82,6 +82,7 @@ Known issues:
 - The user dot no longer lags when panning the map. ([#3683](https://github.com/mapbox/mapbox-gl-native/pull/3683))
 - The Improve This Map tool now uses the same zoom level that is currently being shown in the map view. ([#4068](https://github.com/mapbox/mapbox-gl-native/pull/4068))
 - Fixed a formatting issue in the documentation for `MGLCoordinateBoundsIsEmpty()`. ([#3958](https://github.com/mapbox/mapbox-gl-native/pull/3958))
+- The maximum maximum zoom level is now 21. ([#4417](https://github.com/mapbox/mapbox-gl-native/pull/4417)))
 
 ## iOS 3.1.2
 

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/constants/MapboxConstants.java

@@ -40,7 +40,7 @@ public class MapboxConstants {
     /**
      * The currently supported maximum zoom level.
      */
-    public static final float MAXIMUM_ZOOM = 25.5f;
+    public static final float MAXIMUM_ZOOM = 21.0f;
 
     /**
      * The currently supported maximum tilt value.

src/mbgl/util/constants.cpp

@@ -29,7 +29,7 @@ const double LONGITUDE_MAX = 180;
 const double DEGREES_MAX = 360;
 const double PITCH_MAX = M_PI / 3;
 const double MIN_ZOOM = 0.0;
-const double MAX_ZOOM = 25.5;
+const double MAX_ZOOM = 21.0;
 
 const uint64_t DEFAULT_MAX_CACHE_SIZE = 50 * 1024 * 1024;